Shock absorber



atented Jan. 9, 1951 snooK Asonan Edwin F. Rossman, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application August 13, 1947, Serial No. 768,299

This invention relates to improvements in direct acting, hydraulic shock absorbers.

It is among the objects of the present invention to provide a direct acting hydraulic shock absorber of simplified design and structure in which certain parts have been eliminated and other parts so designed as to perform their own -as well as the functions of the eliminated parts.

A further object of the present invention is to provide a direct acting shock absorber in `which Fig. l is a transverse sectional view taken on the line I-I of Fig. 2.

Fig. 2 is a part longitudinal sectional view of a direct acting hydraulic shock absorber constructed in accordance with the present invention.

Fig. 3 is a fragmentary sectional view illustrating a modified form of construction.

Referring to the drawings the hydraulic shock absorber comprises two concentrically arranged tubular members 2l) and 2|. smaller tubular member provides the working cylinder of the shock absorber, while the larger tubular member 2| `surrounding said cylinder forms the iluid containing reservoir 22 around said cylinder. Both tubular members 20 and 2| are supported by the closure member 23, the tubular member 2| being attached thereto in any suitable manner as for instance by welding. The interior of the cylinder 2|! has its bottom end in communication with the reservoir 22 there being any suitable fluid ilow control mechanism provided between the cylinder and reservoir for controlling the transfer of uid ow therebetween. This mechanism may be of any suitable standard design and because it forms no featured part of the present invention is not illustrated.

As illustrated in Figs. l and 2, an annular row of elongated slots 25 are provided in the wall of the cylinder adjacent the end thereof opposite the closure member 23.

The inner and A plug 26 having a central aperture is presslvoir 22.

1 Claim. (Cl. 18S- 88) and provided with any suitable fluid flow control devices for controlling the iiow of fluid through the piston in one direction or the other, is provided in the cylinder, said piston having a rod 23 attached thereto which extends through and is slidably supported in the aperture in plug 26. The outer end of said rod has an annular cupshaped disc 33 and a mounting ring 3| attached thereto. Mounting ring 3| is provided to attach the movable portion including the piston of the shock absorber to one of the elements lWhose movements the shock absorber is to control, while a similar mounting ring 32 i-s attached to the closure member 33 providing for the attachment of the other relatively movable'portion of the shock absorber including tubes 20 and 2| to the other member whose movement the shock :absorber is adapted to control.

A cover cap 35 is telescopically received by the tubular member 2| and is attached 0thereto in any suitable manner either by screwing thereto or being welded thereto. This cap has a central aperture through which the piston rod 29 extends.

A tubular member 31 slightly larger in diameter than the outside diameter of the cylinder 20 so as` to form a narrow annular space 38 between said cylinder and tubular member extends downwardly into the reservoir so that its end is beneath the normal level in the fluid of the reser- The upper end of said tubular member 31 has an inwardly extending :annular ange 39 which rests upon the upper end of the cylinder 23 as shown in Fig. 2. When the cap 35 is inserted in the tubular member 2|, is engages the inwardly extending annular flange 39 of the tubular member 31 and presses it into clamping engagement upon the end of the cylinder 20 thus this cap 35 clamps and holds the cylinder 20 in proper position relatively to the outer tubular member 2| and in seating engagement with the closure member 23.

Another tubular member 40 :lits about the disc 30 and is attached thereto by welding, this tube 40 surrounding the tubular member 2| and forming a stone guard to protect said tubular member.

In the space between the cover cap 35 and the plug 25 there is provided a packing gland 42 preferably made of any suitable resilient material, this gland surrounding and snugly gripping the peripheral surface of the piston rod 29. A ring-shaped abutment plate 43 engages the one surface of the packing gland 42, the opposite surface engaging the inside of the cover cap 35". Interposed between the abutment plate 43 on the packing gland 42 and the plug 26 there is a coil spring 45, the one end convolution engaging said abutment plate 43, the other end convolution engaging the plug 26 and having portions 46 which enter and seat within the openings 25 in the wall of cylinder v20. This spring exerts a pressure upon the resilient packing gland 42 to urge its annular surface into sealing engagement with the piston rod and to urge its outer surfaces into sealing engagement with the inside of the cover cap 35 and an annular portion of the inner cylinder wall adjacent its end. By the force of the spring 45, this gland is also urged into sealing engagement with that portion of the inwardly extending flange 39 o1 the tubular member 3'! to seal this joint against any uid leaks. VThe portions 46 of the one end convolution of spring 45 forms abutment sections against which the plug 26 abuts thus preventing said plug 26 from moving outwardly in the cylinder.

Any uid leaking from the chamber between piston 28 and plug .25 through the sliding joint .between the piston .rod 2i9 and the aperture in the plug :26. `enters the chamber' in which spring 45 is located then passes through openings or slots 125 into the annular .space 38, between tube i 3*? and cylinder '2Q passing through this passage 3B `to the `fluid within the vreservoir v22. Any air in this .iiuid passes 'through annular passage 38 into `the fluid into the reservoir beneath its level vand then rises in the reservoir 2.2 .to the space .above the Vfluid level in the reservoir where said air Vis trapped.

.In Fig. "3, the cylinder y20 is provided with an annular groove 50 .in its inner wall. The end convolution of spring `l5 snaps `into this groove 5B like any well .known snap ring and thus locks said spring in position. lThis spring also acts las an abutment in this instance preventing outward movement of the plug 26 in the cylinder. To 'connect the .Space orchamber in which the packing '4.2 is located, Vwith the Vreservoir 22, holes '51 'may be provided in the gro-overl wall of the cylindex'.

From the aioregong it may he seen that the .design of the `shock absorber has been simplied and the spring l5 whose normal function is to exert a pressure upon the packing gland 442 to urge it into sealing engagement with various surbination two concentric tubular members, the

inner one forming a working cylinder, the outer one a fluid reservoir; a piston rod guide in said cylinder; a cover cap secured to the outer tubular member and providing a cover for the one end of the cylinder and forming a space above the rod guide; a piston in the cylinder, said piston having a rod extending through the rod guide and the cover cap; slots in the wall of the cylinder adjacent the outer surface of the rod guide, said slots providing communication between the said space and the reservoir; a packing in the said space, engaging surfaces of the rod, the cap and the'interior of the cylinder; and `a spring Iengaging the packing and having portions 'seating in the slots for supporting the spring and providing positive abutments for the rod guide to .prevent its .outward movement in the cylinder.

EDWIN F. ROSSIMAN.

REFERENCES YCITED The following references lare of'record in th fil-e of this `patent:

UNITED STATES vlfAIENTS Number Australia June 2l, 1937 

